Houston-area shelter-in-place lifted after ammonia leak

KATY, Texas (AP) — A shelter-in-place advisory issued in suburban Houston because of a leak of ammonia gas from a refrigeration line at a warehouse was lifted early Sunday afternoon, officials said.

Officials said at a news conference that while air monitoring would continue around the 99 Cents Only Store distribution center in Katy, there wasn't currently a health risk. No injuries were reported.

Emergency responders were called to the warehouse just before 9 p.m. Saturday because of the leak of anhydrous ammonia from an overhead refrigeration line, Harris County Emergency Services District 48 Fire Chief George McAteer said. He said the refrigeration system had been undergoing maintenance.

Initially, the leak was contained to the building, but around 1 a.m. Sunday, air monitoring showed it was leaking out of the 800,000-square-foot (74,322 square meters), Harris County Fire Marshal Laurie Christensen said.

Officials said that it was initially too dangerous for crews to be inside the building because of the flammability of the gas and the respiratory effects from it, but by early afternoon, it had been determined that the tanks had bled off and only residual amounts of ammonia were left.

Harris County Public Health said it issued the shelter in place advisory Sunday morning for the 2 square miles (5 square kilometers) out of an abundance of caution.

Exposure to high concentrations of ammonia in the air can cause burning of the eyes, nose, throat and respiratory track, and can result in blindness, lung damage or death, health officials say, while exposure to lower amounts can result in coughing and irritation of the nose and throat.